Conventionally, each phase of a motor and a control circuit unit for inverter control have been provided separately, each of which are electrically connected using an intermediate harness. However, in recent years, in order to reduce manufacturing time and labor for connecting the intermediate harness, as well as to minimize space, the integration of the motor and the control circuit unit for inverter control has been long studied.
Considering that a high electrical current flows in such a multi-phased motors, Japanese Patent Laid-Open No. 2006-81373 discloses such a design having a bus bar with a large cross-sectional area connecting a terminal connected to each phase of the motor and a terminal on the control circuit unit. In order to achieve high reliability, a bolt has generally been used to connect the terminals to each other either directly or through the intermediate harness.
However, the number of bolts generally correspond to the number of motor phases, i.e. three phases. Therefore, to connect the terminals to each other, a large number of bolts must be tightened, which increases time and labor.